From 7fd9d1862596a5987d54128ed99d4d42b712143e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=98=B8=EF=B8=8F?=
 <29265684+buffermet@users.noreply.github.com>
Date: Mon, 20 Sep 2021 14:04:21 +1000
Subject: [PATCH] fix macParser, MACValidator and IPv4Validator regexp
 selectors + add IPv4BlockValidator

This commit fixes the `network.macParser` and `network.MACValidator` regexp selectors which could validate invalid MAC addresses (e.g. `a:b:c:d:e:f`).

It also introduces a new `IPv4BlockValidator` regexp selector which allows us to distinguish IPv4 address blocks from single IPv4 addresses, as the previous implementation of `IPv4Validator` would also validate IPv4 address blocks (e.g. `10.0.0.0/8`) whilst only being used to validate single IPv4 addresses.

Both IPv4RangeValidator and IPv4Validator were optimized to only match the IPv4 format.

### Validation examples

- `IPv4BlockValidator` validates `10.0.0.0/8`
- `IPv4RangeValidator` validates `10.0-255.0-255.0-255`
- `IPv4Validator` validates `10.0.0.0`
---
 network/net.go | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/network/net.go b/network/net.go
index 61062629..17b26823 100644
--- a/network/net.go
+++ b/network/net.go
@@ -29,11 +29,25 @@ const (
 
 var (
 	BroadcastHw        = []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
-	IPv4Validator      = regexp.MustCompile(`^[0-9\.]+/?\d*$`)
-	IPv4RangeValidator = regexp.MustCompile(`^[0-9\.\-]+/?\d*$`)
-	MACValidator       = regexp.MustCompile(`(?i)^[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}$`)
+	IPv4BlockValidator = regexp.MustCompile(`^` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])` +
+		`/(?:3[0-2]|2[0-9]|[1]?[0-9])` + `$`)
+	IPv4RangeValidator = regexp.MustCompile(`^` +
+		`(?:(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])-)?(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])-)?(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])-)?(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])-)?(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])` + `$`)
+	IPv4Validator = regexp.MustCompile(`^` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])\.` +
+		`(?:25[0-5]|2[0-4][0-9]|[1][0-9]{2}|[1-9]?[0-9])` + `$`)
+	MACValidator = regexp.MustCompile(`(?i)^(?:[a-f0-9]{2}:){5}[a-f0-9]{2}$`)
 	// lulz this sounds like a hamburger
-	macParser   = regexp.MustCompile(`(?i)([a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2}:[a-f0-9]{1,2})`)
+	macParser   = regexp.MustCompile(`(?i)((?:[a-f0-9]{2}:){5}[a-f0-9]{2})`)
 	aliasParser = regexp.MustCompile(`(?i)([a-z_][a-z_0-9]+)`)
 )